A door switch mechanism of a microwave oven, which is a high frequency heating apparatus, will now be described by way of example. Three types of switches, i.e., a latch switch, a door switch, and a monitor switch are incorporated in the door switch mechanism of the microwave oven in consideration to safety in using the microwave oven, and those switches are switched with on and off signals which are obtained with time differences in conjunction with opening and closing of a door.
For example, a door key mounted on an inner surface of the door that exposes and closes an opening on a front side of the microwave oven is provided opposite to switches such as a micro-switch mounted on the main body of the microwave oven, and a switching operation is performed with the door key directly associated with the switches on the main body when the door is closed.
In this case, however, the operation of each switch may be mistimed as a result of a variation of the mounting position of the switch, and an excessively great force may be applied to the switches by an impact that occurs when the door is closed forcefully. For this reason, there has been a possibility of inducing factors causing variation of switching characteristics to disable normal operations of the switches.
A door switch mechanism is also known (JP-A-11-214147), in which two operation pins mounted on an inner surface of a door of a microwave oven are disposed opposite to two respective levers provided on the main body in a face-to-face relationship and in which micro-switches in internal positions are switched through the operation pins and levers in accordance with opening and closing of the door.
In this case, however, since long levers are required, the door switch mechanism as a whole has been large-sized, and a cost increase has resulted because of a great number of components involved. Further, the use micro-switches has involved complicated wiring operations because terminals of three micro-switches are oriented in different respective directions depending on the mounting directions thereof.
Under the circumstance, the invention makes it possible to achieve compactness by incorporating two switches in a single switch case and to achieve a cost reduction through a reduction in the number of components that is achieved by common use of switch components. Further, it is an object of the invention to provide a door switch for a microwave oven having a contact switching structure that is tilted in conjunction with opening and closing of a door to achieve highly accurate performance in switching a switch.